In arthroscopic orthopaedic surgery, it is often necessary to reattach soft tissue to a boney structure. This occurs frequently in the shoulder and other tissues. In these situations where soft tissue is being reattached to bone, it is useful to use a suture anchor device to make the necessary repair. A suture anchor is typically placed into the bone and will not ordinarily pull out. Such suture anchor typically has sutures of its own that can be used to effectively reattach and tie down soft tissue to the bone. This reattachment allows the soft tissue to eventually heal to the bone, and during the process of healing, the suture anchor holds the tissue stationary on the bone.
A suture anchor preferably resists gapping at the tissue bone interface and also resists cyclic loosening of the suture and the tissue from the bone. Anchors can be made of metal, plastic, or absorbable plastics, and designs vary with respect to the number of sutures provided and with respect to whether or not such sutures are allowed to slide within the anchor.
In the normal use of suture anchors, the sutures are passed through the tissue and then knots are tied which allow the anchor to be held into place. A disadvantage can be that suture anchors are normally used for an arthroscopic situation where the anchor is being implanted into a joint where access is limited, and also, where fiber optic arthroscopic cameras are required for visualization by the surgeon. Tying knots in such circumstances can be laborious and time-consuming.
Knotless anchors have been introduced in the surgical device market. However, such anchors may have certain technical pitfalls which the present invention seeks to remedy.
The knotless anchors that have been produced to this point typically involve arthroscopically drilling a hole in a bone, removing the guide from that area, passing sutures through soft tissue. The surgeon must then re-find the hole and insert some sort of push-in anchor or screw-in anchor. As the anchor is screwed or pushed in, it varies as to how much tension is actually developed in the soft tissue. Certain joint geometries and locations make using these types of anchors difficult and/or less effective than desired. The process of drilling the hole and then having to re-find it after removing a specific guide (once the sutures have been passed through the tissue) is a technical difficulty for certain repair locations that have limited access. Additionally, using these types of anchors in certain locations can cause damage to adjacent tissue, which is undesirable.
Accordingly, an anchor design which eliminates the need to tie knots and which provides internal cinching mechanisms would be desirable.